Pressure vessel



Jan. 11, 1966 w. J. D. ESCHER PRESSURE VESSEL Original Filed July 27,1961 4 Sheets-Sheet 1 1 g m f' j- INVENTOR WILLIAM J. D. ESCHER BY q)Lvvl 3 4 M. A/M

ATTORNEYS Jan. 11, 1966 w. J. D. ESCHER 3,228,187

PRESSURE VESSEL Original Filed July 27, 1961 4 Sheets-5heet 2 INVENTORW/LL/AM J. D EscHER BY ww w WMKM ATTORNEYS Jan. 11, 1966 w. J. D. ESCHER3,228,137

PRESSURE VESSEL Original Filed July 27, 1961 4 Sheets-Sheet :5

/8 E5. I3 INVENTOR.

W/LL/AM J. D. [SC/745R 9 M -1 BY J? F. JM

ATTORNEYS Jan. 11, 1966 w. J. D. ESCHER 3,223,187

PRESSURE VESSEL Original Filed July 27. 1961 4 Sheets-Sheet 4 INVENTORWILLIAM J D ESCHER BY Q #16,, g on? flaw ATTORNEYS United States Patent3,228,187 PRESSURE VESSEL William J. D. Escher, 1624 Stoddard Ave.,Thousand Oaks, Calif.

Original application July 27, 1961, Ser. No. 127,405, now Patent No.3,189,500. Divided and this application Feb. 16, 1965, Ser. No. 433,231

8 Claims. (Cl. 6035.6) (Granted under Title 35, U.S. Code (1952), sec.266) This application is a division of co-pending application Serial No.127,405 which was filed July 27, 1961 and issued as U.S. Patent No.3,189,500.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

This invention relates generally to the improved construction ofpressure vessels and more particularly relates to improvements in theconstruction of pressure vessels of the rocket thrust chamber type.

Multiple-wall pressure vessels are generally known to the art andinclude rocket thrust chambers fabricated with an inner liner wall andan external wall spaced therefrom to provide coolant passagestherebetween. The fabrication of these types of constructions includeswelding or brazing together a plurality of tubes which are externallywrapped with wire or suitable metallic bands and externally wrapping aplurality of juxtaposed channels or ribs disposed on a liner. Thesepressure vessel constructions are both complex as well astime-consuming, and they require the use of strategic and relativelyheavy materials which often do not permit flexibility to achieve designvariations in a particular model thrust chamber, e.g. cooling passagecross sectional area.

Accordingly, among the objects of this invention are im- :provements inthe construction of pressure vessels that will simplify and economizemanufacture and provide increased flexibility in design variationwithout sacrificing structural strength. A further object of thisinvention is to provide a lightweight high performance thrust chamberwhich can be fabricated over a wide range of production rates.

Briefly, in accordance with this invention, there is provided acomposite wall construction for a pressure vessel, such as a rocketthrust chamber, which embodies a relatively thin-walled liner shellsurrounded and enclosed by an outer shell of wound fiberglass or otherstructural filaments, e.g. metal filaments, plastic filaments, etc.,disposed in spaced relation from the liner. The liner shell is supportedon the outer shell by a plurality of laterally spaced, radiallyprojecting pin members which coact in tension between the shells. Duringand after winding, the outer shell is sealed by impregnation with asuitable resin which is cured to provide a chamber having anuninterrupted good heat transfer liner surface structurally supported onan outer shell which is capable of containing a coolant at higher thanthe internal pressure of the chamber. The chamber is fabricated bybonding the pin members to the external surface of the liner shell andthen applying a suitable rnelt-out material to that surface to a depthsuitable for the local cooling passage height, which leaves the freeextremities of the pin members exposed. Fiberglass filaments are thenwound about the solidified melt-out material to a predetermined depthstill leaving the free extremities of the pin members exposed, afterwhich suitable head members are mounted on the free extremities of thepin members or equivalent heading means are employed and the winding ofthe fiberglass filament is completed to a predetermined thicknessenclosing the pin members, the melt-out material and the liner shell.The melt-out material is then melted or dissolved and removed and theexternal, wound roving shell which is impregnated with a suitable resinis cured to seal the space which the melt-out material had occupied.Various items of hardware, including channel-forming ribs, inlet andoutlet or manifold members and the like, may be incorporated in theoverall structure as the fabrication progresses.

In the drawings:

FIGS. 1, 2, 3 and 4 progressively show the fabrication of a typicalpressure vessel in accordance with this invention from inner liner tosupporting outer shell with the tension members coacting therebetween;

FIGS. 5 through 10, inclusive, show successively the mounting of a pinon the inner liner in FIG. 5, the application of the melt-out materialin FIG. 6, the first stage of win-ding of fiberglass filaments in FIG.7, the application or forming of the head member on the pin in FIG. 8,the last stage of winding of filament in FIG. 9, and the removal of themelt-out material in FIG. 10;

FIG. 11 is a diagrammatic, partial sectional View, illustrating twostages in the fabrication of a typical pressure vessel in accordancewith this invention;

FIG. 12 is an end view of the pressure vessel of FIG. 11;

FIG. 13 is a compound assembly of a pair of nozzles for a. rocket thrustchamber made in accordance with this invention;

FIG. 14 is a compound assembly of a pair of combustion chambers for arocket thrust chambermade in accordance with this invention;

FIG. 15 diagrammatically illustrates an assembly technique for combininga combustion chamber with a nozzle to form a rocket thrust chamber inaccordance with this invention;

FIG. 16 is a partial view, in section, taken along lines 1818 in FIGS.13 or 14 of the drawings;

FIG. 17 is another view of the structural portion of FIG. 16illustrating the separation of the nozzle or combustion chamber portionsafter fabrication is completed;

FIG. 18 is a partial View, in section, of the end of one of the nozzleor combustion chamber portions of FIG. 17 illustrating the mounting of amanifold end-piece thereon;

FIG. 19 is a diagrammatic illustration of a portion of an integralrocket thrust chamber made in accordance with this invention,illustrating the composite wall construction with the liner shellsupported in tension on the outer shell in :partial section;

Referring now more particularly to FIGS. 1 through 4 of the drawingsthere is illustrated a preferred structural embodiment and method offabrication in accordance with this invention. A liner shell 10 ofuninterrupted thingauge metal selected to provide a good heat transfersurface and having suitable end-pieces 13 and 13a shown in FIG. 1. Theliner shell 10 may be formed in any conventional manner and its externalsurface milled, for example by etching with a material reactive with themetal, to form suitable welding bosses (not shown) adapted to supporttension pins 11 in a manner to be hereinafter more fully described. Thewelding bosses are preferably milled in a pretermined pattern on theexternal surface of the liner shell 10 and, for purposes of thisdescription, may be assumed to be uniformly spaced laterally from eachother. FIG. 2 of the drawings diagrammatically illustrates the pins 11disposed radially on the outer surface of the liner shell 10 with oneextremity stud-welded or otherwise suitably bonded to the welding bosseson the external surface of the shell 10. Thereafter, as diagrammaticallyshown in FIG. 3, a suitable melt-out material 12 is applied to theentire external surface of the liner shell 10 to a depth sufficient toleave the free extremities of the pins exposed. The melt-out material 12may be any suitable material that can be subsequently removed by theapplication of increased temperature or dissolving agents, and in thepreferred embodiment shown, a low melting material, e.g.

a bismuth-tin alloy M.P. 281 F. is sprayed onto the liner shell 10.Thereafter, the liner shell 10, with its pins 11 mounted in place and acoating of melt-out material 12 applied to its external surface, ismounted on a suitable mandrel and wound with a resin-impregnatedfiberglass filament 14 to provide an outer shell 15 as diagrammaticallyshown in FIG. 4.

The foregoing steps are also diagramamtically shown in FIGS. 5 throughin relation to a portion of a liner shell adjacent one of the pinmembers, wtih the successive steps of mounting the pin, applying themelt-out material and then applying the preliminary winding offiberglass filament shown successively in FIGS. 5, 6 and 7. As bestshown in FIGS. 8, 9 and 10 of the drawings respectively, the exposedtips of the pins are then provided with head members 16, which may beconventional push-on type fastening clip. At this point it is possiblebut not necessary to apply a sealing film of appropriate material to theshell to act as a barrier to liquid or gas leakage under subsequentconditions Wherein the cooling passage is pressurized. A succeedingwinding of fiberglass filament is then applied to enclose and bind thepin members and their heads in tension between the liner shell and thewound filaments of fiberglass; and finally, the melt-out material isremoved from the space between the outer shell formed by the successivewindings of fiberglass filaments and the liner shell 10 by applyingsuitably high temperature or a dissolving agent to the material in amanner well known to those skilled in the art. Instead of push-on clips,the ends of the pins may be split and spread to form heads.

Thereafter, the outer shell may be further impregnated with a suitableresin, such as an epoxy resin (reaction product of bisphenol A withepichlorohydrin, and reactively cured with a polyamine), as a finishsurface, the entire composition wall assembly cured to seal the spacebetween the outer and liner shells and to provide structural strengthand rigidity to the shell. The curing of the resin-impregnatedfiberglass filament outer shell may be accomplished simultaneously withthe removal of the melt-out material by appropriate application of heat.Instead of the epoxy resins, which are preferred for the purposeshereof, other thermosetting impregnating resins, e.g.phenol-formaldehyde; amino-plast resins, e.g. melamine-aldehyde resins,silicone resins, polyesters, e.g. Laminac 4134 manufactured by AmericanCyanamid.

The resulting composite structure is diagrammatically shown in partialsection in FIGS. 11 and 12 of the drawings, which show a portion of theliner shell 10 prior to the construction of the external or outer shelland another portion with the outer shell in place. Suitable end-pieces17 and 18 which form manifolds at each end of the vessel are shownmounted in place; such end-pieces being put in place after the pinmembers 11 have been welded to the liner shell 10 and before theapplication of the melt-out material 12 and outer shell 15 of fiberglassfilaments. These end-piece manifolds show the manner in which thecoolant material may be suplied to and removed from the space betweenthe liner shell and the outer shell when in use.

While the fabrication technique and resulting structural embodiment isapplicable to any type of pressure vessel, such as jacketed storagetanks, heat exchangers, and other types of combustion units, the presentinvention is principally concerned with the fabrication of rocket thrustchambers and a technique for fabricating such chambers is progressivelyillustrated in FIGS. 13 through 18, inclusive, of the drawings.Asdistinguished from the conventional pressure vessel illustrated inFIGS. 1 through 4 and 11 and 12, the rocket thrust chamber type ofpressure vessel has a predetermined variable surface configuration asshown in FIG. 15 to provide a combustion chamber 19 at one end and athrust nozzle 20 at the other end, both integrally joined through areduced diameter throat portion 21.

In accordance with this invention, a preferred technique for assemblingthe component parts of a rocket thrust chamber consists of making asub-assembly of a pair of nozzle portions 20 and 20A in back-to-backrelation as best shown in FIG. 13 and another sub-assembly of thecombustion chamber portions 19 and 19A in back-toback relation as bestshown in FIG. 14. Each of these sub-assemblies are then fabricated inthe manner hereinbefore described to provide the composite double-wallconstruction of a liner shell supported by pin members or spokes intension on a primary structural member in the form of an external orouter shell of wound fiberglass filaments. As best shown in FIG. 16, theparts of the sub-assemblies are preferably joined together at theirwide-mouth extremities by any suitable means and after the pin membersand outer shell are applied, the subassembly is separated as shown inFIG. 17 and various hardware items, such as manifold end-pieces, areapplied as best shown in FIG. 18 of the drawings. The end portions ofthe outer shell are cut away as shown by the dotted lines 22 and 22A inFIG. 17, and when the endpiece 24 is placed in position as shown in FIG.18, a further winding 23 of resin-impregnated fiberglass filamentsecures the end-piece in place.

Whether the rocket thrust chamber is fabricated in accordance with thetechnique shown and described in connection with FIGS. 13 through 18inclusive, or integrally formed as a single unit as shown in FIG. 19, itis possible but not necessary to form coolant passages 26 extendingaxially along the outer surface of the liner shell in the space betweenthe liner shell 10 and the outer shell 15. These passages may be formedby mounting suitable longitudinal metal strips 25 in juxtaposed spacedrelation about the external surface of the liner shell, each metal striphaving a depth corresponding to the depth of the space between the linershell and the outer shell, thereby forming juxtaposed channels (FIG.19). Such channels may also be formed as hereinbefore noted by formingribs or other wall-separators around the periphery of the liner shell.When the outer shell 15 is applied, coolant fluid may be suppliedthrough the manifold at one extremity of the rocket thrust chamber andpassed (arrow) along the surface of the liner shell through theappropriate channels for removal or injection at the other extremity asa liquid propellant.

Thus, there has been provided in accordance with this invention, acomposite, multi-walled pressure vessel consisting of an uninterruptedheat transfer surface formed by a liner shell which is in turn supportedon pins or spokes in tension on a lightweight outer shell havingsufiicient structural strength to contain a gaseous or liquid coolant orpropellant in passages formed therebetween at a pressure higher than thecombustion chamber pressure. The fabrication is economical and simpleand permits flexibility in design, and the resulting improvedconstruction is relatively light in weight and employs nonstrategicmaterials in a manner that does not sacrifice structural strength orother desirable mechanical characteristics required in the normalapplication of such vessels.

I have shown and described what I consider to be the preferredembodiment of my invention along with suggested modifications, and it isclear that other changes and modifications may be made by those skilledin the art without departing from the scope of my invention as definedby the appended claims.

I claim:

1. A pressure vessel comprising,

a relatively thin-walled liner shell,

an outer shell of wound filaments disposed in spaced surroundingrelation from the liner shell,

means impregnating said wound outer shell and coating therewith to sealthe space between the outer and liner shells, and

means coacting in tension between the impregnated outer shell and theliner shell to support the liner shell thereon.

2. The pressure vessel of claim 1 wherein said outer shell consists ofwound fiberglass filaments.

3. The pressure vessel of claim 1 wherein said impregnating meansincludes a thermosetting resin.

4. The pressure vessel of claim 1 wherein said tension means includes aplurality of laterally spaced, radially disposed pins of substantiallyrigid material, each having a bond to the liner at one extremity and theother extremity interlocked within the filaments of the outer shell.

5. A rocket thrust chamber comprising,

a relatively thin-walled liner shell,

an outer shell of wound filaments disposed in spaced surroundingrelation from the liner shell,

means impregnating said wound outer shell and coating therewith to sealthe space between the outer and liner shells,

means coacting in tension between the impregnated outer shell and theliner shell to support the liner shell thereon, and

means forming axially disposed and juxtaposed liquid conduits in thespace between the outer and liner shells.

6. The rocket thrust chamber of claim 5 wherein said conduit-formingmeans includes circumferentially spaced axially extending partitions.

7. A pressure vessel comprising,

a thin-walled metal liner,

a plurality of spaced metal pins extending radially outward from saidliner,

a filament-wound outer shell disposed in spaced surrounding relationfrom said liner in contact with said pins, and

a head member secured to the outer extremity of each of said pinsimbedded in said outer shell for bonding the same to said pin.

8. A pressure vessel having an integral cooling passage 5 comprising,

a thin-walled metal liner having an outwardly facing surface forreceiving a layer of melt-out material having a thickness equal to theheight of the cooling passage,

a plurality of spaced rigid protuberances having a length greater thanthe thickness of the layer of melt-out material extending outward fromsaid outwardly facing surface of said liner,

a filament-wound outer shell disposed in spaced surrounding relationfrom said liner in contact with the outer extremities of saidprotuberances and the outer surface of the layer of melt-out materialprior to the removal thereof, and

means imbedded in said outer shell for bonding the same to saidprotuberances.

References Cited by the Examiner UNITED STATES PATENTS 2,744,043 5/1956Ramberg 35.6 X 2,958,183 11/1960 Singelmann 6()35.6 3,044,257 7/1962Shesta 6035.6 3,082,611 3/1963 Alvis et al 6035.6 X 3,131,535 5/1964Hensley 6035.6

MARK NEWMAN, Primary Examiner.

CARLTON R. CROYLE, Examiner.

5. A ROCKET THRUST CHAMBER COMPRISING, A RELATIVELY THIN-WALLED LINERSHELL, AN OUTER SHELL OF WOUND FILAMENTS DISPOSED IN SPACED SURROUNDINGRELATION FROM THE LINER SHELL, MEANS IMPREGNATING SAID WOUND OUTER SHELLAND COATING THEREWITH TO SEAL THE SPACE BETWEEN THE OUTER AND LINERSHELLS, MEANS COACTING IN TENSION BETWEEN THE IMPREGNATED OUTER SHELLAND THE LINER SHELL TO SUPPORT THE LINER SHELL THEREON, AND MEANSFORMING AXIALLY DISPOSED AND JUXTAPOSED LIQUID CONDUITS IN THE SPACEBETWEEN THE OUTER AND LINER SHELLS.